21582395065 has 64 divisors (see below), whose sum is σ = 33124515840. Its totient is φ = 13108631040.

The previous prime is 21582395063. The next prime is 21582395099. The reversal of 21582395065 is 56059328512.

It is not a de Polignac number, because 21582395065 - 2¹ = 21582395063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21582395063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4213576 + ... + 4218694.

It is an arithmetic number, because the mean of its divisors is an integer number (517570560).

Almost surely, 2^21582395065 is an apocalyptic number.

It is an amenable number.

21582395065 is a deficient number, since it is larger than the sum of its proper divisors (11542120775).

21582395065 is a wasteful number, since it uses less digits than its factorization.

21582395065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5422.

The product of its (nonzero) digits is 648000, while the sum is 46.

The spelling of 21582395065 in words is "twenty-one billion, five hundred eighty-two million, three hundred ninety-five thousand, sixty-five".